The patient's nervous tension and apprehension aggravates and augments the flow of saliva and seriously hampers the performance of dental services. Cleaning, coating, prophylactic and other dental work performed on the teeth can also cause considerable blood and saliva flow and these fluids along with cuttings and other foreign matter must be removed. A wide variety of saliva and foreign matter ejectors have been proposed to alleviate these problems. Typical constructions are disclosed in the following U.S. Pat. Nos.: 342,042 Rowney; 2,028,381 Dewitt; 2,830,371 Dahl; 2,844,873 Bober; 24,693 Thompson Re-issue; 2,950,533 Sommerstein; 3,078,578 White; 3,396,468 Dayhoff. Each of the foregoing devices as well as other commercial variants available to the dental profession and coming to my attention are subject to serious deficiencies and shortcomings. For example, many of these devices, such as those shown by Rowney and Sommerstein, are supported merely by gravity in the oral cavity or must be held or manipulated by the patient, the dentist or his assistant. In recognition of these shortcomings proposals have been made for ejectors equipped with means engagable with the patient's jaw to hold the ejector seated against the bottom of the oral cavity. Examples of devices of this type are shown by White, Dewitt, Dahl and Bober. Not only do such devices impose objectionable pressure on oral cavity tissues and the underside of his chin but they increase the patient's discomfort and lack provision for preventing closure of the mouth. They have inadequate and unacceptable provision for keeping selected denture surfaces dry and uncontaminated by saliva, blood, detritus and moisture from the patient's breath. Dayhoff and Thompson show saliva ejectors incorporating some means for holding the oral cavity open. Dayhoff's ejector is formed entirely of semi-flexible plastic tubing straddling the upper and lower arches and supports a flexible elastic sheet or dam having cut outs through which the teeth project and includes a vertical wall to isolate the tongue. This contruction is bulky, difficult and time consuming to install and uncomfortable. Thompson proposes a jaw spacer accessory which can be inserted in orifices of a perforated tubular saliva ejector to hold the latter pressed against the floor of the oral cavity. It lacks lingual guard protection and any provision for draining saliva from the parotid salivary duct and the upper molars.